This invention relates to a fuel supplying system for plural-cylinder internal combustion engines and more particularly to an improved and simplified arrangement for providing enrichment fuel to a multi-cylinder engine.
In many forms of engines, in addition to the normal fuel supplying system for the engine, there is provided an enrichment system for supplying additional fuel in response to certain specific conditions such as a running condition of the engine, like acceleration, or an ambient condition, such as temperature for cold starting. Many times, this enrichment system is generally separate from the normal charge forming system for the engine. That is, the engine may be provided with either a carburetor or a fuel injection system that provides the bulk of the fuel requirements for the engine. However, a separate enrichment system is incorporated for supplying the enrichment fuel. For example, with two-cycle internal combustion engines, it is common to provide these separate enrichment systems to supply fuel for acceleration, anti-knock purposes, cold starting or cold running. Although the fuel for the enrichment system may be drawn from the same source as supplies the main charge former, frequently the fuel is introduced into a different place in the engine's induction system.
Where the engine has plural cylinders, it has been the practice to provide the enrichment fuel in the manifold system for the cylinders. Therefore, it obviously is necessary to provide considerable piping for delivering fuel to each of the manifold passages that are supplied with enrichment fuel. Frequently, there supply conduits are external to the engine and this can give rise to a number of disadvantages.
It is, therefore, a principal object of this invention to provide an improved and simplified fuel enrichment arrangement for a multiple cylinder internal combustion engine.
It is a yet further object of this invention to provide an enrichment system for a multiple cylinder internal combustion engine that is simple and which yet insures that equal fuel will be delivered to all of the induction passages served.